There is an increasing number of consumer products being operated by rechargeable cells such as nickel cadmium cells. These products require cells with a plurality of physical sizes and electrical characteristics. The above-mentioned patent, U.S. Pat. No. 4,009,429 and application, Ser. No. 877,299, describe charging systems for AA, C, D and 9 volt size batteries which employ battery carrying modules adapted to close couple with a charge current source or with such a source and an adapter. In any case, the charge current source is provided with the familiar two blade electrical contacts for insertion into the sockets of a standard duplex wall outlet, which serves as a source of 110-120V AC current.
The total suspended weight of a direct plug-in electrical device, such as a battery charger or a specialty transformer as used with toys, is limited by the ability of the blades of the electrical device to directly support the weight of the device through their frictional engagement with the socket receptacle of the outlet. In fact, Underwriters Laboratories' standards limit this weight generated torque to 9 inch ounces. In those instances where the torque generated by the weight of the plug-in electrical device is in excess of 9 inch ounces, additional support means must be provided. It is recognized in the Underwriters Laboratories standards that the center screw which attaches the cover plate to the outlet may be used to support additional weight, on the order of an additional twenty ounces. However, the disadvantage in the use of the cover plate attachment screw is the inconvenience in removing and replacing the screw each time the electrical device such as a transformer/charger is used. Generally, such devices are plugged in and removed in repeated cycles, and thus the inconvenience associated with removing and replacing the cover plate screw, as well as the cover plate, is readily apparent.